1. Field of the Invention
The invention relates to a disc-record player comprising a device for scanning rotating disc-shaped information carriers, comprising a frame, a turntable, which is rotatable about an axis of rotation during operation and which comprises a supporting surface for information carriers having a circumferential edge, and a centering device for bringing said information carriers into a centered position relative to a centering axis, the centering device comprising a pair of pivotal arms which are each movable about respective pivotal axes which extend parallel to the centering axis, which pivotal arms each comprising a centering element constructed to cooperate with the circumferential edges of said information carriers.
The invention also relates to a centering device for use in a disc-record player.
2. Description of the Related Art
A disc-record player comprising a centering device is known from U.S. patent specification Ser. No. 2,508,715 (herewith incorporated by reference). The known disc-record player is suitable for playing phonograph records of two types having different diameters. For this purpose the player comprises a turntable, a pick-up arm, and a centering device for centering the phonograph records relative to the turntable. The centering device comprises two pivotal arms which are coupled to each other and a fixed and a pivotable stop. The pivotal arms each have a cylindrical centering element for cooperation with the circumferential edge of records of both types when the relevant record is slid into and out of the player. The fixed and the pivotable stop serve for limiting the loading movement of a large and a small record respectively, the pivotable stop being coupled to the pivotal arms via a mechanism. In the known centering device the two cylindrical-centering elements in conjunction with the fixed stop and the pivotable stop respectively serve for approximately centering a phonograph record relative to the turntable. Exact centering of a record relative to the turntable is effected by means of an axially movable centering spindle, the dimensioning being such that in the operating position the record situated on the turntable is clear of the centering elements and the stops.
Using the prior-art device in modern disc-record players by means of which optical discs such as CDs can be inscribed and/or read would give rise to some problems. For example, owing to the presence of stops the prior-art centering device requires a disc-position detection which operates very accurately in order to ensure that a disc being loaded into the player is stopped duly to preclude a collision with one of the stops, which may damage the vulnerable optical disc. Another disadvantage of the prior-art centering device is the comparatively large space needed to bring the pivotable stop into its non-operational position, which makes it difficult to construct a disc-record player of small overall height. A further disadvantage is that the stops are situated at locations which in optical disc-record players are generally occupied by an optical scanning unit. Moreover, it is to be noted that in the known disc-record player the means proposed for disengaging the disc-record situated on the turntable from the centering elements and the stops are inadequate to obtain the desired and generally required clearance between an optical disc and the centering means.